Description

The ftpaccess file is used to configure the operation of ftpd(8).

Access Capabilities

autogroup <groupname> <class> [<class> ...]

If an ANONYMOUS user is a member of any of <class>, the ftp server will perform a setegid() to <groupname>. This allows access to group-and-owner-read-only files and directories to a particular class of anonymous users. <groupname> is a valid group from /etc/group (or wherever mechanism your getgrent(2) library routine uses).

class <class> <typelist> <addrglob> [<addrglob> ...]

Define <class> of users, with source addresses of the form <addrglob>. Multiple members of <class> may be defined. There may be multiple "class" commands listing additional members of the class. If multiple "class" commands can apply to the current session, the first one listed in the access file is used. Failing to define a valid class for a host will cause access to be denied. <typelist> is a comma-separated list of any of the keywords "anonymous", "guest" and "real". If the "real" keyword is included, the class can match users using FTP to access real accounts, and if the "anonymous" keyword is included the class can match users using anonymous FTP. The "guest" keyword matches guest access accounts (see "guestgroup" for more information)

<addrglob> may be a globbed domain name or a globbed numeric address. It may also be the name of a file, starting with a slash ('/'), which contains additional address globs, as well as in the form address:netmask or address/cidr.

Placing an exclamation (!) before an <addrglob> negates the test. For example:

    class rmtuser real !*.example.com

will classify real users from outside the example.com domain as the class rmtuser. Use care with this option. Remember, the result of each test is OR'ed with other tests on the line.

deny <addrglob> <message_file>

Always deny access to host(s) matching <addrglob>. <message_file> is displayed. <addrglob> may be "!nameserved" to deny access to sites without a working nameserver. It may also be the name of a file, starting with a slash ('/'), which contains additional address globs, as well as in the form address:netmask or address/cidr.

guestgroup <groupname> [<groupname> ...]

guestuser <username> [<username> ...]

realgroup <groupname> [<groupname> ...]

realuser <username> [<username> ...]

For guestgroup, if a REAL user is a member of any of <groupname>, the session is set up exactly as with anonymous FTP. In other words, a chroot() is done, and the user is no longer permitted to issue the USER and PASS commands. <groupname> is a valid group from /etc/group (or whatever mechanism your getgrent(3) library routine uses).

The user's home directory must be properly set up, exactly as anonymous FTP would be. The home directory field of the passwd entry is divided into two directories. The first field is the root directory which will be the argument to the chroot(2) call. The second half is the user's home directory relative to the root directory. The two halves are separated by a "/./".

For example, in /etc/passwd, the real entry:

    guest1:<passwd>:100:92:Guest Account:/ftp/./incoming:/etc/ftponly

When guest1 successfully logs in, the ftp server will chroot(/ftp) and then chdir(/incoming). The guest user will only be able to access the directory structure under /ftp (which will look and act as / to guest1), just as an anonymous FTP user would.

The group name may be specified by either name or numeric ID. To use a numeric group ID, place a '%' before the number. Ranges may be given. Use an asterisk to mean all groups.

guestuser works like guestgroup, except uses the user name (or numeric ID).

realuser and realgroup have the same syntax, but reverse the effect of guestuser and guestgroup. They allow real user access when the remote user would otherwise be determined a guest.

For example:

    guestuser *
    realgroup admin

causes all non-anonymous users to be treated as guest, with the sole exception of users in the admin group who are granted real user access.

nice <nice-delta> [<class>]

Adjust the process nice value of the ftpd server process by the indicated <nice-delta> value if the remote user is a member of the named <class>. If <class> is not specified, then use <nice-delta> as the default adjustment to the ftpd server process nice value. This default nice value adjustment is used to adjust the nice value of the server process only for those users who do not belong to any class for which a class-specific `nice' directive exists in the ftpaccess file.

defumask <umask> [<class>]

Set the umask applied to files created by daemon if the remote use is a member of the named class. If <class> is not specified, then use the umask as the default for classes which do not have one specified.

tcpwindow <size> [<class>]

Set the TCP window size for the data connection. This can be used to control network traffic. For instance, slow PPP dialin links may need smaller TCP windows to speed up throughput. If you don't know what this does, don't play with it.

keepalive <yes|no>

Set the TCP SO_KEEPALIVE option for data sockets. This can be used to control network disconnect. Yes: set it. No: use system default (usually off). You probably want to set this.

timeout accept <seconds>

timeout connect <seconds>

timeout data <seconds>

timeout idle <seconds>

timeout maxidle <seconds>

timeout RFC931 <seconds>

Set various timeouts.

Accept (default 120 seconds): how long the daemon will wait for an incoming (PASV) data connection.

Connect (default 120 seconds): how long the daemon will wait attempting to establish an outgoing (PORT) data connection. This effects the actual connetion attempt. The daemon makes several attempts, sleeping a while between each, before completely giving up.

Data (default 1200 seconds): how long the daemon will wait for some activity on the data connection. You should keep this long because the remote client may have a slow link and there can be quite a bit of data queued for the client.

Idle (default 900 seconds): how long the daemon will wait for the next command. The default can also be overridden by the command line -a option. This access clause overrides both.

MaxIdle (default 1200 seconds): the SITE IDLE command allows the remote client to establish a higher value for the idle timeout. This sets the upper limit the client may request. The default can also be overridden by the command line -A option. This access clause overrides both.

RFC931 (default 10 seconds): the maximum time the daemon allows for the entire RFC931 (AUTH/ident) conversation. Setting this to zero (0) completely disables the daemon's use of this protocol. The information obtained via RFC931 is recorded in the system logs and not actually used in any authentication.

file-limit [<raw>] <in|out|total> <count> [<class>]

Limit the number of data files a user in the given class may transfer. The limit may be placed on files in, out or total. If no class is specified, the limit is the default for classes which do not have a limit specified. The optional raw parameter applies the limit to the total traffic rather than just data files.

data-limit [<raw>] <in|out|total> <count> [<class>]

Limit the number of data bytes a user in the given class may transfer. The limit may be place on bytes in, out or total. If no class is specified, the limit is the default for classes which do not have a limit specified. The optional raw parameter applies the limit to total traffic rather than just data files.

limit-time {*|anonymous|guest} <minutes>

Limit the total time a session can take. By default, there is no limit. Real users are never limited.

guestserver [<hostname>]

Controls which hosts may be used for anonymous or guest access. If used without <hostname>, denies all guest or anonymous access to this site. More than one <hostname> may be specified. Guest and anonymous access will only be allowed on the named machines. If access is denied, the user will be asked to use the first <hostname> listed.

limit <class> <n> <times> <message_file>

Limit <class> to <n> users at times <times>, displaying <message_file> if the user is denied access. Limit check is performed at login time only. If multiple "limit" commands can apply to the current session, the first applicable one is used. Failing to define a valid limit, or a limit of -1, is equivalent to unlimited. <times> is in same format as the times in the UUCP L.sys file.

noretrieve [absolute|relative] [class=<classname>] ... [-] <filename> <filename> ...

Always deny retrieve-ability of these files. If the files are a path specification (i.e. begins with '/' character) then only those files are marked un-gettable, otherwise all files with matching the filename are refused transfer. For example:

    noretrieve /etc/passwd core

specifies no one will be able to get the file /etc/passwd whereas they will be allowed to transfer a file `passwd' if it is not in /etc. On the other hand no one will be able to get files named `core' wherever they are.

Directory specifications mark all files and sub-directories in the named directory un-gettable. The <filename> may be specified as a file glob. For example:

    noretrieve /etc /home/*/.htaccess

specified no files in /etc or any of its sub-directories may be retrieved. Also, no files named '.htaccess' anywhere under the /home directory may be retrieved.

The optional first parameter selects whether names are intepreted as absolute or relative to the current chroot'd environment. The default is to intepret names beginning with a slash as absolute.

The noretrieve restrictions may be placed upon members of particular classes. If any class= is specified the named files are only non-retrievable if the current user is a member of any of the given classes.

allow-retrieve [absolute|relative] [class=<classname>]... [-] <filename> ...

Allows retrieval of files which would otherwise be denied by noretrieve.

loginfails <number>

After <number> login failures, log a "repeated login failures" message and terminate the FTP connection. Default value is 5.

private <yes|no>

After user logs in, the SITE GROUP and SITE GPASS commands may be used to specify an enhanced access group and associated password. If the group name and password are valid, the user becomes (via setegid()) a member of the group specified in the group access file /etc/ftpgroups.

The format of the group access file is:

    access_group_name:encrypted_password:real_group_name

where access_group_name is an arbitrary (alphanumeric + punctuation) string. encrypted_password is the password encrypted via crypt(3), exactly like in /etc/passwd. real_group_name is the name of a valid group listed in /etc/group.

NOTE: For this option to work for anonymous FTP users, the ftp server must keep /etc/group permanently open and the group access file is loaded into memory. This means that (1) the ftp server now has an additional file descriptor open, and (2) the necessary passwords and access privileges granted to users via SITE GROUP will be static for the duration of an FTP session. If you have an urgent need to change the access groups and/or passwords *NOW*, you just kill all of the running FTP servers.

Informational Capabilities

greeting full|brief|terse

greeting text <message>

Allows you to control how much information is given out before the remote user logs in. 'greeting full' is the default and shows the hostname and daemon version. 'greeting brief' whose shows the hostname. 'greeting terse' simply says "FTP server ready." Although full is the default, brief is recommended.

The 'text' form allows you to specify any greeting message you desire. <message> can be any string; whitespace (spaces and tabs) is converted to a single space.

banner <path>

Works similarly to the message command, except that the banner is displayed before the user enters the username/password. The <path> is relative to the real system root, not the base of the anonymous FTP directory.

WARNING: use of this command can completely prevent non-compliant FTP clients from making use of the FTP server. Not all clients can handle multi-line responses (which is how the banner is displayed).

hostname <some.host.name>

Defines the default host name of the ftp server. This string will be printed on the greeting message and every time the %L magic cookie is used. The host name for virtual servers overrides this value. If not specified, the default host name for the local machine is used.

email <name>

Defines the email address of the ftp archive maintainer. This string will be printed every time the %E magic cookie is used.

message <path> {<when> {<class> ...}}

Define a file with <path> such that ftpd will display the contents of the file to the user login time or upon using the change working directory command. The <when> parameter may be "LOGIN" or "CWD=<dir>". If <when> is "CWD=<dir>", <dir> specifies the new default directory which will trigger the notification.

The optional <class> specification allows the message to be displayed only to members of a particular class. More than one class may be specified.

There can be "magic cookies" in the readme file which cause the ftp server to replace the cookie with a specified text string:

    %T      local time (form Thu Nov 15 17:12:42 1990)
    %F      free space in partition of CWD (kbytes)
              [not supported on all systems]
    %C      current working directory
    %E      the maintainer's email address as defined in ftpaccess
    %R      remote host name
    %L      local host name
    %u      username as determined via RFC931 authentication
    %U      username given at login time
    %M      maximum allowed number of users in this class
    %N      current number of users in this class
    %B      absolute limit on disk blocks allocated
    %b      preferred limit on disk blocks
    %Q      current block count
    %I      maximum number of allocated inodes (+1)
    %i      preferred inode limit
    %q      current number of allocated inodes
    %H      time limit for excessive disk use
    %h      time limit for excessive files
 ratios:
    %xu     Uploaded bytes
    %xd     Downloaded bytes
    %xR     Upload/Download ratio (1:n)
    %xc     Credit bytes
    %xT     Time limit (minutes)
    %xE     Elapsed time since login (minutes)
    %xL     Time left
    %xU     Upload limit
    %xD     Download limit

The message will only be displayed once to avoid annoying the user. Remember that when MESSAGEs are triggered by an anonymous FTP user, the <path> must be relative to the base of the anonymous FTP directory tree.

readme <path> {<when> {<class>}}

Define a file with <path> such that ftpd will notify user at login time or upon using the change working directory command that the file exists and was modified on such-and-such date. The <when> parameter may be "LOGIN" or "CWD=<dir>". If <when> is "CWD=<dir>", <dir> specifies the new default directory which will trigger the notification. The message will only be displayed once, to avoid bothering users. Remember that when README messages are triggered by an anonymous FTP user, the <path> must be relative to the base of the anonymous FTP directory tree.

The optional <class> specification allows the message to be displayed only to members of a particular class. More than one class may be specified.

Logging Capabilities

log commands <typelist>

Enables logging of individual commands by users. <typelist> is a comma-separated list of any of the keywords "anonymous", "guest" and "real". If the "real" keyword is included, logging will be done for users using FTP to access real accounts, and if the "anonymous" keyword is included logging will done for users using anonymous FTP. The "guest" keyword matches guest access accounts (see "guestgroup" for more information).

log transfers <typelist> <directions>

Enables logging of file transfers for either real or anonymous FTP users. Logging of transfers TO the server (incoming) can be enabled separately from transfers FROM the server (outbound). <typelist> is a comma-separated list of any of the keywords "anonymous", "guest" and "real". If the "real" keyword is included, logging will be done for users using FTP to access real accounts, and if the "anonymous" keyword is included logging will done for users using anonymous FTP. The "guest" keyword matches guest access accounts (see "guestgroup" for more information). <directions> is a comma-separated list of any of the two keywords "inbound" and "outbound", and will respectively cause transfers to be logged for files sent to the server and sent from the server.

log security <typelist>

Enables logging of violations of security rules (noretrieve, .notar, ...) for real, guest and/or anonymous users. <typelist> is a comma-separated list of any of the keywords "anonymous", "guest" and "real". If the "real" keyword is included, logging will be done for users using FTP to access real accounts, and if the "anonymous" keyword is included logging will done for users using anonymous FTP. The "guest" keyword matches guest access accounts (see "guestgroup" for more information).

log syslog

log syslog+xferlog

Redirects the logging messages for incoming and outgoing transfers to syslog. Without this option the messages are written to xferlog.

syslog+xferlog sends the transfer log messages to both the system log and the xferlog.

Upload/Download ratios

In order for any of these commands to work, you must compile WU-FTPD with --enable-ratios.

ul-dl-rate <rate> [<class> ...]

Specify Upload/Download ratio (1:rate). When ftp user uploaded 1 bytes, (s)he can take <rate> bytes. By default, there is no ratio.

dl-free <filename> [<class> ...]

The file <filename> can be downloaded freely (=ignoring the ratio)

dl-free-dir <dirname> [<class> ...]

All files in the directory <dirname> and its subdirectories can be downloaded freely (=ignoring the ratio) Note that both dl-free and dl-free-dir are relative to the system's root, not the chroot environment.

Miscellaneous Capabilities

alias <string> <dir>

Defines an alias, <string>, for a directory. Can be used to add the concept of logical directories.

For example:

    alias rfc: /pub/doc/rfc

would allow the user to access /pub/doc/rfc from any directory by the command "cd rfc:". Aliases only apply to the cd command.

cdpath <dir>

Defines an entry in the cdpath. This defines a search path that is used when changing directories.

For example:

    cdpath /pub/packages
    cdpath /.aliases

would allow the user to cd into any directory directly under /pub/packages or /.aliases directories. The search path is defined by the order the lines appear in the ftpaccess file.

If the user were to give the command:

    cd foo

the directory will be searched for in the following order:

    ./foo
    an alias called "foo"
    /pub/packages/foo
    /.aliases/foo

The cd path is only available with the cd command. If you have a large number of aliases you might want to set up an aliases directory with links to all of the areas you wish to make available to users.

compress <yes|no> <classglob> [<classglob> ...]

tar <yes|no> <classglob> [<classglob> ...]

Enables compress or tar capabilities for any class matching any of <classglob>. The actual conversions are defined in the external file FTPLIB/ftpconversions.

shutdown <path>

If the file pointed to by <path> exists, the server will check the file regularly to see if the server is going to be shut down. If a shutdown is planned, the user is notified, new connections are denied after a specified time before shutdown and current connections are dropped at a specified time before shutdown. <path> points to a file structured as follows:

    <year> <month> <day> <hour> <minute> <deny_offset> <disc_offset>
    <text>

where

    <year> is any year > 1970
    <month> 0-11 <---- LOOK!
    <hour> 0-23
    <minute> 0-59

<deny_offset> and <disc_offset> are the offsets in HHMM format before the shutdown time that new connections will be denied and existing connections will be disconnected.

<text> follows the normal rules for any message (see "message"), with the following additional magic cookies available:

    %s      time system is going to shut down
    %r      time new connections will be denied
    %d      time current connections will be dropped

all times are in the form: ddd MMM DD hh:mm:ss YYYY. There can be only one "shutdown" command in the configuration file.

The external program ftpshut(8) can be used to automate the process of generating this file.

daemonaddress <address>

If the value is not set, then the server will listen for connections on every IP addresses, otherwise it will only listen on the IP address specified.

Use of this clause is discouraged. It was added to support a single site's needs. It will completely break virtual hosting and the syntax is likely to change in a future version of the daemon.

virtual <address> <root|banner|logfile> <path>

Enables the virtual ftp server capabilities. The <address> is the ip address of the virtual server. The second argument specifies that the <path> is either the path to the root of the filesystem for this virtual server, the banner presented to the user when connecting to this virtual server, or the logfile where transfers are recorded for this virtual server. If the logfile is not specified the default logfile will be used. All other message files and permissions as well as any other settings in this file apply to all virtual servers.

NOTE: Your operating system may not support this feature. It has been tested on BSD/OS, Solaris 2.X and Linux.

The <address> may also be specified as the hostname rather than the IP number. This is strongly discouraged since, if DNS is not available at the time the FTP session begins, the hostname will not be matched.

virtual <address> <hostname|email> <string>

Sets the hostname shown in the greeting message and STATus command, or the email address used in message files and on the HELP command, to the given <string>.

virtual <address> allow <username> [<username> ...]

virtual <address> deny <username> [<username> ...]

Normally, real and guest users are not allowed to log in on the vitual server unless they are guests and chroot'd to the virtual root. The users listed on the virtual allow line(s) will be granted access. All users can be granted access by giving '*' as the username. The virtual deny clauses are processed after the virtual allow clauses and are used to deny access to specific users when all users were allowed.

virtual <address> private

Normally, anonymous users are allowed to log in on the virtual server. This option denies them access.

virtual <address> passwd <file>

Use a different passwd file for the virtual domain. The daemon needs to be compiled with --enable-passwd (or OTHER_PASSWD) for this option to work.

virtual <address> shadow <file>

Use a different shadow file for this virtual domain. The daemon needs to be compiled with --enable-passwd (or OTHER_PASSWD) for this option to work.

defaultserver deny <username> [<username> ...]

defaultserver allow <username> [<username> ...]

Normally, all users are allowed access to the default (non-virtual) FTP server. Use defaultserver deny to revoke access for specific users; specify '*' to deny access to all users. Specific users can then be allowed using defaultserver allow.

defaultserver private

Normally, anonymous users are allowed on the default (non-virtual) FTP server. This statement disallows anonymous access.

The virtual and defaultserver allow, deny and private clauses provide a means to control which users are allowed access on which FTP servers.

passive address <externalip> <cidr>

Allows control of the address reported in response to a PASV command. When any control connection matching the <cidr> requests a passive data connection (PASV), the <externalip> address is reported. NOTE: this does not change the address the daemone actually listens on, only the address reported to the client. This feature allows the daemon to operate correctly behind IP-renumbering firewalls.

For example:

    passive address 10.0.1.15   10.0.0.0/8
    passive address 192.168.1.5 0.0.0.0/0

Clients connecting from the class-A network 10 will be told the passive connection is listening on IP-address 10.0.1.15 while all others will be told the connection is listening on 192.168.1.5

Multiple passive addresses may be specified to handle complex, or multi-gatewayed, networks.

passive ports <cidr> <min> <max>

Allows control of the TCP port numbers which may be used for a passive data connection. If the control connection matches the <cidr> a port in the range <min> to <max> will be randomly selected for the daemon to listen on. This feature allows firewalls to limit the ports which remote clients may use to connect into the protected network.

<cidr> is shorthand for an IP address in dotted-quad notation followed by a slash and the number of left-most bits which represent the network address (as opposed to the machine address). For example, if you're using the reserved class-A network 10, instead of a netmask of 255.0.0.0 use a CIDR of /8 as in 10.0.0.0/8 to represent your network.

pasv-allow <class> [<addrglob> ...]

port-allow <class> [<addrglob> ...]

Normally, the daemon does not allow a PORT command to specify an address different than that of the control connection. And it does not allow a PASV connection from another address.

The port-allow clause provides a list of addresses which the specified class of user may give on a PORT command. These addresses will be allowed even if they do not match the IP-address of the client-side of the control connection.

The pasv-allow clause provides a list of addresses which the specified class of user may make data connections from. These addresses will be allowed even if they do not match the IP-address of the client-side of the control connection.

lslong <command> [<options> ...]

lsshort <command> [<options> ...]

lsplain <command> [<options> ...]

The lslong, lsshort and lsplain clauses allow specification of the command and options used to generate directory listings. Note the options cannot contain spaces and the defaults for these clauses are generally correct; use lslong, lsshort or lsplain only if absolutely necessary.

mailserver <hostname>

Specify the name of a mail server which will accept upload notifications for the FTP daemon. Multiple mail servers may be listed; the daemon will attempt to deliver the upload notification to each, in order, until one accepts the message. If no mail servers are specified, localhost is used. This option is only meaningful if anyone is to be notified of anonymous uploads (see incmail).

incmail <emailaddress>

virtual <address> incmail <emailaddress>

defaultserver incmail <emailaddress>

Specify email addresses to be notified of anonymous uploads. Mutltiple addresses can be specified; each will receive a notification. If none are specified, no notifications are sent.

If addresses are specified for a virtual host, only those addresses will receive notification up anonymous uploads on that host. Otherwise, notifications will be sent to the global addresses.

Defaultserver addresses only apply when the FTP session is not using one of the virtual hosts. In this way, you can receive notifications for your default anonymous area, but not see notifications to virtual hosts which do not have their own notifications.

mailfrom <emailaddress>

virtual <address> mailfrom <emailaddress>

defaultserver mailfrom <emailaddress>

Specify the sender's email address for anonymous upload notifications. One one address may be specified. If no mailfrom applies, email is sent from the default mailbox name 'wu-ftpd'. To avoid problems if the recipient attempts to reply to a notification, or if downstream mail problems generate bounces, you should ensure the mailfrom address is deliverable.

Permission Capabilities

chmod <yes|no> <typelist>

delete <yes|no> <typelist>

overwrite <yes|no> <typelist>

rename <yes|no> <typelist>

umask <yes|no> <typelist>

Allows or disallows the ability to perform the specified function. By default, all users are allowed.

<typelist> is a comma-separated list of any of the keywords "anonymous", "guest", "real" and "class=". When "class=" appears, it must be followed by a classname. If any class= appears, the <typelist> restriction applies only to users in that class.

passwd-check <none|trivial|rfc822> (<enforce|warn>)

Define the level and enforcement of password checking done by the server for anonymous ftp.

    none      no password checking performed.
    trivial   password must contain an '@'.
    rfc822    password must be an rfc822 compliant address.
    warn      warn the user, but allow them to log in.
    enforce   warn the user, and then log them out.

deny-email <case-insensitive-email-address>

Consider the e-mail address given as an argument as invalid. If passwd-check is set to enforce, anonymous users giving this address as password cannot log in. That way, you can stop users from having stupid WWW browsers use fake addresses like IE?0User@ or mozilla@. (by using this, you are not shutting out users using a WWW browser for ftp - you just make them configure their browser correctly.) Only one address per line, but you can have as many deny-email addresses as you like.

path-filter <typelist> <mesg> <allowed_charset> {<disallowed regexp> ...}

For users in <typelist>, path-filter defines regular expressions that control what a filename can or can not be. There may be multiple disallowed regexps. If a filename is invalid due to failure to match the regexp criteria, <mesg> will be displayed to the user. For example:

    path-filter anonymous /etc/pathmsg ^[-A-Za-z0-9._]*$ ^\. ^-

specifies that all upload filenames for anonymous users must be made of only the characters A-Z, a-z, 0-9, and "._-" and may not begin with a "." or a "-". If the filename is invalid, /etc/pathmsg will be displayed to the user.

upload [absolute|relative] [class=<classname>]... [-] <root-dir> <dirglob> <yes|no> <owner> <group> <mode> [dirs|nodirs] [<d_mode>]

Define a directory with <dirglob> that permits or denies uploads.

If it does permit uploads, all newly created files will be owned by <owner> and <group> and will have their permissions set according to <mode>, existing files which are overwritten will keep their original ownership and permissions.

Directories are matched on a best-match basis.

For example:

    upload /var/ftp *              no
    upload /var/ftp /incoming      yes ftp daemon 0666
    upload /var/ftp /incoming/gifs yes jlc guest  0600 nodirs

would only allow uploads into /incoming and /incoming/gifs. Files that were uploaded to /incoming would be owned by ftp/daemon and would have permissions of 0666. File uploaded to /incoming/gifs would be owned by jlc/guest and have permissions of 0600. Note that the <root-dir> here must match the home directory specified in the password database for the "ftp" user.

The optional "dirs" and "nodirs" keywords can be specified to allow or disallow the creation of new subdirectories using the mkdir command.

Note that if the upload command is used, directory creation is allowed by default. To turn it off by default, you must specify a user, group and mode followed by the "nodirs" keyword as the first line where the upload command is used in this file.

If directories are permitted, the optional <d_mode> determines the permissions for a newly created directory. If <d_mode> is omitted, the permissions are inferred from <mode> or are 0777 if <mode> is also omitted.

The upload keyword only applies to users who have a home directory (the argument to the chroot() ) of <root-dir>. <root-dir> may be specified as "*" to match any home directory.

The <owner> and/or <group> may each be specified as "*", in which case any uploaded files or directories will be created with the ownership of the directory in which they are created.

The optional first parameter selects whether <root-dir> names are intepreted as absolute or relative to the current chroot'd environment. The default is to intepret <root-dir> names as absolute.

You can specify any number of 'class=<classname>' restrictions. If any are specified, this upload clause only takes effect if the current user is a member of one of the classes.

Please read the upload.configuration.HOWTO for a complete discussion of how to configure your server to allow uploading files.

throughput <root-dir> <subdir-glob> <file-glob-list> <bytes-per-second> <bytes-per-second-multiply> <remote-glob-list>

Define files via comma-seperated <file-glob-list> in subdir matched by <subdir-glob> under <root-dir> that have restricted transfer throughput of <bytes-per-second> on download when the remote hostname or remote IP address matches the comma-seperated <remote-glob-list>.

Entries are matched on a best-match basis.

For example:

    throughput /e/ftp *    *      oo   -   *
    throughput /e/ftp /sw* *      1024 0.5 *
    throughput /e/ftp /sw* README oo   -   *
    throughput /e/ftp /sw* *      oo   -   *.foo.com

would set maximum throughput per default, but restrict download to 1024 bytes/s for any files under /e/ftp/sw/ which are not named README. The only exceptions are remote hosts from within the domain foo.com which always get maximum throughput. Every time a remote client has retrieved a file under /e/ftp/sw/ the bytes per seconds of the matched entry line are internally multiplied by a factor, here 0.5. So when the remote client retrieves its second file it is served with 512 bytes/s, the third time with only 254 bytes/s, the fourth time with only 128 bytes/s and so on.

The string "oo" for the bytes per second field means no throughput restriction. A multiply factor of 1.0 or "-" means no change of the throughput after every successful transfer.

Note that the <root-dir> here must match the home directory specified in the password database for the "ftp" user. The throughput keyword only applies to users who have a home directory (the argument to the chroot() ) of <root-dir>.

anonymous-root <root-dir> [<class>]

<root-dir> specifies the chroot() path for anonymous users. If no anonymous-root is matched, the old method of parsing the home directory for the 'ftp' user is used. If no <class> is specified, this is the root directory for anonymous users who do not any other anonymous-root specification. Multiple classes may be given on the line. If an anonymous-root is chosen for the user, the 'ftp' user's home directory in the <root-dir>/etc/passwd file is used to determine the initial directory and the 'ftp' user's home directory in the system-wide /etc/passwd is not used.

For example:

    anonymous-root /home/ftp
    anonymous-root /home/localftp localnet

causes all anonymous users to be chroot()'d to the directory /home/ftp then, if the 'ftp' user exists in /home/ftp/etc/passwd, their initial CWD is that home directory. Anonymous users in the class localnet, however, are chroot()'d to the directory /home/localftp and their initial CWD is taken from the 'ftp' user's home directory in /home/localftp/etc/passwd.

guest-root <root-dir> [<uid-range>]

<root-dir> specified the chroot() path for guest users. If no guest-root is is matched, the old method of parsing the user's home directory is used. If no <uid-range> is specified, this is the root directory for guest users who do not match any other guest-root specification. Multiple uid ranges may be given on the line. If a guest-root is chosen for the user, the user's home directory in the <root-dir>/etc/passwd file is used to determine the initial directory and their home directory in the system-wide /etc/passwd is not used.

<uid-range> specifies numeric UID values. Ranges are specified by giving the lower and upper bounds (inclusive), separated by a dash. Omitting the lower bound means "all up to", and omitted the upper bound means "all starting from".

For example:

    guest-root /home/users
    guest-root /home/staff %100-999 sally
    guest-root /home/users/frank/ftp frank

causes all guest users to chroot() to /home/users then starts each user in their home directory specified in /home/users/etc/passwd. Users in the range 100 through 999, inclusive, and user sally, will be chroot()'d to /home/staff and the CWD will be taken from their entries in /home/staff/etc/passwd. The single user frank will be chroot()'d to /home/users/owner/ftp and the CWD will be from his entry in /home/users/owner/ftp/etc/passwd.

Note that order is important for both anonymous-root and guest-root. If a user would match multiple clauses, only the first applies; with the exception of the clause which has no <class> or <uid-range>, which applies only if no other clause matches.

deny-uid <uid-range> [...]

deny-gid <gid-range> [...]

allow-uid <uid-range> [...]

allow-gid <gid-range> [...]

These clauses allow specification of UID and GID values which will be denied access to the ftp server. The allow-uid and allow-gid clauses may be used to allow access for uid/gid which would otherwise be denied. These checks occur before all others. Deny is checked before allow. The default is to allow access. Note that in most cases, this can remove the need for an /etc/ftpusers files. For example:

    deny-gid %-99 %65535
    deny-uid %-99 %65535
    allow-gid ftp
    allow-uid ftp

denies ftp access to all privileged or special users and groups on a Linux box except the anonymous 'ftp' user/group. In many cases, this can eliminate the need for the /etc/ftpusers file. Support for that file still exists so it may be used when changing /etc/ftpaccess is not desired.

Throughout the ftpaccess file, any place a single UID or GID is allowed, either names or numbers may be used. To use numbers, put a '%' before it. In places where a range is allowed, put the '%' before the range.

restricted-uid <uid-range> [...]

restricted-gid <gid-range> [...]

unrestricted-uid <uid-range> [...]

unrestricted-gid <gid-range> [...]

These clauses control whether or not real or guest users will be allowed access to areas on the FTP site outside their home directories. They are not meant to replace the use of guestgroup and guestuser. Instead, use these to supplement the operation of guests. The unrestricted-uid and unrestricted-gid clauses may be used to allow users outside their home directories who would otherwise be restricted.

An example of the use of these clauses shows their intended use. Assume user 'dick' has a home directory /home/dick and 'jane' /home/jane:

    guest-root /home dick jane
    restricted-uid dick jane

While both dick and jane are chroot'd to /home, they cannot access each other's files because they are restricted to their home directories.

Whereever possible, in situations such as this example, try not to rely solely upon the ftp restrictions. As with all other ftp access rules, try to use directory and file permissions to backstop the operation of the ftpaccess configuration.

site-exec-max-lines <number> [<class> ...]

The SITE EXEC feature traditionally limits the number of lines of output which may be sent to the remote client. This clause allows you to set this limit. If omitted, the limit is 20 lines. A limit of 0 (zero) implies no limit; be very careful if you choose to remove the limit. If a clause is found matching the remote user's class, that limit is used. Otherwise, the clause with class '*', or no class given, is used. For example:

    site-exec-max-lines 200 remote
    site-exec-max-lines 0 local
    site-exec-max-lines 25

limits output from SITE EXEC (and therefore SITE INDEX) to 200 lines for 'remote' users, specifies there is no limit at all for 'local' users, and sets a limit of 25 lines for all other users.

dns refuse_mismatch <filename> [override]

Refuse FTP sessions when the forward and reverse lookups for the remote site do not match. Display the named file (like a message file), admonishing the user. If the optional override is specified, allow the connection after complaining.

dns refuse_no_reverse <filename> [override]

Refuse FTP sessions when there is no reverse DNS entry for the remote site. Display the named file (like a message file), admonishing the user. If the optional override is specified, allow the connection after complaining.

dns resolveroptions [options]

The resolveroptions option allows you to tweak name server options. The line takes a series of flags as documented in resolver(3) (with the leading RES_ removed). Each can be preceded by an optional + or -. For example,

    dns resolveroptions +aaonly -dnsrch

turns on the aaonly option (only accept authoritative answers) and turns off the dnsrch option (search the domain path).

Files

FTPLIB/ftpaccess

See Also

ftpd(8), umask(2), ftplog(5), ftpconversions(5), ftpshut(8)